1. Field of the Invention
The present invention pertains to energy storage and, more particularly, to devices and methods for storing electrical energy using organic materials.
2. Discussion of the Prior Art
Electrical energy is conventionally stored in batteries wherein electrons are passed via electrodes into an electrolyte by means of an ionic modification within the battery. Conventional batteries utilize a metallic electrode interacting with an ionic solution, or electrolyte, such that, as the electrode dissolves, electrons are released for ionic storage in the electrolyte; and, accordingly, such batteries are referred to herein as ionic batteries since electrical energy is stored and released thereon on an ionic basis. In discharging ionic batteries, the electrons are released at the electrodes. Such conventional ionic batteries have the disadvantages of being slow to charge, being able to discharge large currents for only brief periods, requiring electrodes made of specific and usually rare metals, and consuming the electrodes thereby limiting battery lifetime.
Many attempts have been made to increase the efficiency, charging rate and lifetime of ionic batteries; however, such attempts have not met with success in that, while they have improved some characteristics of such batteries, they still rely on the ionic process of energy storage thereby retaining relatively long charge times and consumable electrodes due to the inherent low mobility of ions in the electrolyte.
One area where substantial efforts have been made to improve electrical energy storage is for use with electric vehicles, and most of these efforts have been directed toward improving batteries to provide efficient operation of electric motors and conservation of energy. To date, however, while many sophisticated battery systems have been devised, such systems still suffer from decreased lifetimes relative to charging and discharging cycles, long charging times, and the requirement of materials expensive to produce and, in many cases, hazardous to produce.
Research in melanins has resulted in the discovery of switching characteristics providing high and low resistance states in response to voltage as described by John E. McGinness et al. in an article entitled "Amorphous Semiconductor Switching in Melanins," 1974, Science, Vol. 183, pp. 853-855, by C. H. Culp et al. in an article in the Journal of Applied Physics, 1975, Vol. 46, pp. 3658-3659, by J. Filatous et al. in an article entitled "Thermal and Electronic Contributions to Switching in Melanins," 1976, Biopolymers, Vol. 15, pp. 2309-2312, and by F. W. Cope in an article entitled "Inversions of Emulsions of Aggregated Electrons as a Possible Mechanism for Electrical Switching in Wet Melanin," 1977, Physiological Chemistry and Physics, Vol. 9, pp. 543-546. V. Horak et al. discuss oxidation reduction of dopa melanin in an article entitled "A Study of The Oxygen Reduction State of Synthetic Dopa Melanin," 1971, Molecular Pharmacology, Vol. 1, pp. 429-433, and characteristics of melanin are further discussed by P. R. Crippa in an article "Struttura Electronica e Proprieta Funzionali Delle Malanine," Att. Accademia Gioenia de Catania, Serie VII, Vol. XI, 1979. Studies of melanin and their electrical characteristics have produced only the recognition of the switching characteristics thereof; and, after disclosure of such switching characteristics, studies of the electrical characteristics of melanins failed to yield any information leading to other beneficial electrical characteristics of melanins even by those on the forefront of the semiconductor field.